Merge "regex: avoid a namespace collision with C23 <float.h>." into main am: 3211cac9a7

Original change: https://android-review.googlesource.com/c/platform/external/llvm/+/3428946

Change-Id: Ia6525d7a67bb3b896fd237426e80d09a27995ec5
Signed-off-by: Automerger Merge Worker <[email protected]>
diff --git a/lib/Support/regcomp.c b/lib/Support/regcomp.c
index ebde64f..ac7bb8c 100644
--- a/lib/Support/regcomp.c
+++ b/lib/Support/regcomp.c
@@ -150,6 +150,7 @@
 #else
 #define	DUPMAX	255
 #endif
+#undef INFINITY // Android-added: avoid collision with C23 <float.h> INFINITY (via <limits.h>)
 #define	INFINITY	(DUPMAX + 1)
 
 #ifndef NDEBUG